Black Project Spontaneous & Wild Ales – In February 2014, Black Project began as a side project of a brewery called Former Future. Within 1.5 years, it was the main focus.

Focusing entirely on sour beers, Black Project is a master of its craft and attracted a line at the Great American Beer Festival that was 30 people deep before the doors even opened. (Volunteers abandoned their positions so they could get a taster before the brewery ran out.)

The brewery’s offerings are available, on occasion, out of state. But the real challenge these days is ensuring they have enough to meet demand from local customers. That makes the decision to attend the GABF more difficult each year, since every beer poured at the festival means there’s one less available at the brewery. And, with beers that take this long to perfect, that’s noteworthy.

“Ultimately, from a business perspective, we’re worried if we’re going to have enough for the taproom,” says co-founder James Howat. -FORTUNE